Furnace for heating hydrocarbon fluids



Feb. 18, 1941- J. H. RICKERMAN FURNACE FOR HEATING HYDROCARBON FLUIDSFiled' Nov. 17, 1938 BY 6.56M-

ATTORN EY Patented Feb. 18, V1941 UISIITED PATENT OFFICE i i y#2,232,136 FURNACE Foa :Bume HYDRocARBoN L L 'i John Hermanav Rickerman,RiverjEdge, N. J., as-

'signor' to GasolinejrProducts Company, Inc., Jersey City, N. .i avcorporation of Delaware i Applicationnovember-17,1938,seria1No.24o,941

- '5 9 claims. (ci. 19e- 116) especially adaptedv for heating normallygaseous hydrocarbons to conversion temperatures to convert them intohigher boiling normally liquid hydrocarbons containing constituents`within the gasoline boiling range. p t

A furnace embodying the features of my invention in-cludes a radiant:heating section for heating hydrocarbon uids in heater-tubes by exposingthe heaterA tubes to direct `radiant heat.

l5 Burners are provided for supplying hot products of combustion to thefurnace. The hydrocarbon uids are raised to a conversion temperature andthen passed through heater tubes in-a convection heating section in thefurnace for completing the conversion reaction. i y

The hot products yof combustion leave the radiant heating `section vthrough a passageway formed by the'upperportion of a bridgewall and avertical walli of the furnaceextending `above v the roof of theradiantheating section. Prevheater tubes are positionedin thispassageway for preheatinghydrocarbon fluids before passing `them throughheater tubes in the radiant -heating section while at the same time thehot products of combustion lose some of `theirheat and have theirtemperature lowered.l i t All or a part of the products of combustionleaving the passageway containing the preheater tubes are then passedover heater Ltubes inthe convection heating section for supplying heatto the hydrocarbon fluids in the heaterft'ubes toeffect the desiredextent of conversion. :Means are provided for removing part of thecombustion gases to control the heating of the hydrocarbon fluids in theheater tubes in the convection `heating section. This meansis arrangedinthe upper portion of the convection heating section and includes aby-pass for by-passingsome `of the `hot products of combustion leavingthe radiant heating section and passing over thebridge wall. The by-passis in alinement with the passage over the bridge Wall so that hotproducts of combustion to be removed may directly pass through thelby-pass outlet in substantially Aa straight line ow. In

this way the overheating of i the hydrocarbon fluids in the convectionheater tubes is prevented. After passing over the convectionheatertubes, the products of combustion are passed to a stack. Myinvention also includes a method of heating hydrocarbon fluids whichincludes prehe'ating hydrocarbon fluids by using all the hot products ofcombustion leaving the radiant section and controlling the heating ofthe hydrocarbon fluids in the convectionheating section by controllingthe volume of combustion gases passing to the con- 5 vection heatingsection from the radiant heating section.- f

In; i the drawing there is diagrammatically shown; a transverse verticalcross section of a furnace embodying my invention. 10

Referring'now to the drawing, the reference character I0 designates abox type or rectangular furnacek provided with a radiant heating sectionYIl and a convection heating section l2 separated from vthe radiantheating section by a hollow 15 bridge wall I4. The bridge wall extendsabove the roof of the radiant heatingsection ll and forms one side of apassageway i6 through which the hot products of combustion leave theradiant `heating section as will be hereinafter more fully 20 described.j 1 Y, y

The radiant heating section is' provided with c ,heater tubes yalong itsboundary l surfaces. Roof tubes 20 and `22, `wall tubes 24,`floor tubes26 and bridge wall tubes 28` are arranged longitudinally `25`offthegradiant heatingy section along the respective boundaryjsurfacesthereof. In somevinstances certainof these banks of -heater tubes may beomitted if desired. Suitable return bends `are provided. Hydrocarbonfluids to be heated `30 to conversion temperatures are passed throughinlets Boland then through banks of preheating tubes `32 and-34, thehydrocarbon fluids passing througheach bank of tubes in parallel fiow.The

`prehe'ating tubes 32 and 34 are arranged longi- 35 ltudi'lally of the'furnace.` The preheating tubes ,32 and 34 are arranged'inthe passagewayI6 adjacent the lupper .portion ofthe bridge wall lthrough which all thehot products of combustion leave thev radiant `heating section Il. Ifdesired, 40

the hydrocarbon fluids may be passed through the preheating section inasingle stream instead of plural streams. t t

Aflterbeing preheated,` the. hydrocarbon fluids are?v passed through4.the heater tubes in .the `45 radiant heating sectionin plural streamsas will y. be hereinafter described in more detail. The hydrocarbonfluids after being heated in the radiant ,heating section pass inyseparate streams through .i banks .of tubes 38, 4B, 42 and 44 in theconvection 50 heating section vl2 and `leave the tubes through outlets46 and 48 to other apparatus for the separation of desired constituents.

Suitable burners 50are preferablymounted in I the walls of the radiantheating section and pro- :55

vide means for burning fuel such as a hydrocarbon gas for supplyingradiant heat for the radiant heating section. The burners are preferablyarranged in opposite Walls of the radiant section and the burners in onewall may be out of alinement with the burners in the opposite wall sothat the burning fuel streams from opposite walls are slightly offsetwith respect to each other and do not collide in the centers of theradiant heating section. Other arrangements of burners may be used.

The roof 52 of the radiant heating section IiI is lower than the topportion 54 of the bridge Wall I4. A vertical Wall 55 extends .upwardlyfrom the end portion of roof '52 nearest the bridge wall I4 to a pointabove .the Stop portion '5.'4 of the bridge wall. The vertical wall' 55is spaced from the bridge wall I4 and lis vsubstantially parallelthereto to provide the passageway -I5 above referred to which conveysthe hot products of lcombustion away from the radiant heating sectionII.

' The furnace further includes a roof 62 positioned above the bridgewall I4 and convection heating section I2. This roof 62 is spaced fromthe upper portion 54 of the bridge wall I4 and provides a passageway 64which forms a continuation of Ythe* passageway I6 for conducting hotproducts of combustion from the radiant heating section and preheatingsection. 'Ihe hot products of combustion in passing over the prehea-tertubes 32 and 34 in the passageway I6 lose some of their heat, and allora part of the combustion gases are then -passed over the convectionheater tubes 38, 40, 42 and 44 for heating fthe hydrocarbon yiiuids inthe convection heater tubes. After passing over the convection heatertubes, the Waste gases 'are passed through -rlue vt5 for passage to astack (not shown).

When'the hot products of combustion after having passed over thepreheating tubes 32 Iand v34 are at ytoo-high a temperature, thehydrocarboniiuids lin the convection heater tubes or soaking sectionmight be overheated and therefore itis desirable that -a part ofthecombustion gases -be removed. For this purpose a by-pass '6B .isprovi-ded in the upper portion of the convection section I2 above *theconvection heater tubes. The by-pass 66 has a damper 68 for controllingthe volume of combustion gases to be passed to the stack without passingover the convection heater tubes. It will be seen that the by-pass 6Bisin alinement with the horizontal portion 64 of the passageway I6 leadingfrom the radiant heating section and in this way the hot products ofcombustion are easily removed from the furnace in a straight line flowand the amount of combustion gases to be by-passed-is easily controlled.'Ihe by-pass 65 andA damper 68 provide means for controlling the amountof hot products of combustion to be passed through the convectionheating section and thereby control the heating of the hydrocarbonfluids passing through heater tubes in the convection heating section.Duey to the arrangement ofthe by-pass 65, overheating of the hydrocarbonuids in the convection heater tubes in the convection heating section I2is prevented. Also, by having a controlled lower temperature in theconvection heating section, I am enabled to use cheaper refractorymaterial therein.'

The roof 52 of the radiant section II is provided With a downwardlydirected, curved deiiecting member 'I2 extending longitudinally of thefurnace for deiiecting the hot products `of heated to conversiontemperatures are passed through inlets 30 and pass through thepreheating tubes 32 `an-d 34 so that each stream passes in .parallel:How through the banks of preheater tubes fand becomes preheated. Thesepreheater tubes are `positioned in the passageway I6 located between theupper portion of the bridge wall I4 and the vertical Wall 56 of thefurnace and are heated by the hot products of combustion as they leavethe lradiant heating section I I. All of the hot products of combustionfrom the radiant heating section pass through the passageway I6 and overthe preheating tubes v32 and 34.

One ofthe streams of preheated hydrocarbon fluids passing '-through lthebank .34 of the preheater tubes is passed through line T4, throughbridge =.wall tubes 2.8, through line I6 and roof 'tubes '20 and leavesthe radiant heating section through line 18. The other stream passingthrough the bank -32 .of the preheater .tubes is passed through line 82,through the floor tubes 26, through `line 84 and then through wall tubes24 and roof k-tubes 22 and is then merged with the previously describedstream passing through Yline 'I8 from the radiant heating section. 'I'he-heater tubes in the radiant heating section are exposed Yto directradiant heat and during their passage through these tubes in thelradiant heating section, the hydrocarbon fluids are raised to 2 Aaconversion temperature.

v'Ihesingle ystream of hydrocarbon fluids pass- 4ling `through line 'I8'is substantially at a conver- `sionfternperature and 'is thensubdivided into a 'plurality -of streams and the separate streams arepassed through the banks of tubes 38, 40, 42 and 44 in Vthe convectionheating section which lfunctions as a soaking section. The hydrocarbo'nnuids are passed through the convecetionheating tubes in four `streamsand may be later merged andleave 'the convection heating section as adouble stream through outlets 4S 'and' 48. If desired the hydrocarbonfluids `may be passed through lthe furnace in a single'stream.

The hot `products -of combustion pass over 'th-e3 preheater tubesin the-preheating section -IS and then pass through fthe passageway 64 abovethe bridge wall I4.

It is important to -control the lheating of the hydrocarbon nuids'passing through the lconvection heater -tubes Vin vthe 'convectionsection I?. to; prevent overheating 4of `the vhydrocarbon fluids andformation `and deposition of coke in the -conveotion heater tubes Awhenthe hot -products of combustion leaving the radiant heating section IIYare at 'too high a temperature for heating `vthe fluids in theconvection heating section, the

damper 68 Ain the -by-pass ltiIi is opened to permit by-passing vof'some of the hot products of combustion Abeforethey ycontact tubes 38,40, 42 and f v44 inthe convection heating lsection I2. The by-pass '664forms a l continuationy of the horizontal portion N6431iAthefpassageway I6 so that the Vyhot `pr,od1.ictsof :combustion *areeasily removed 'from the 'furnace in a rsubstantially Vstraight line 75and a convection heating section separated by a and the heating oftheuidsjin the convection heating section is easily andaccurately-controlled. A f y In some instances it may be desirable to,mix the streams of fluid passing through banks-of tubes 38, 40, 42 andM`in the convection section I2 in order to insure uniform heating of thestreams. Lines 8o and 82 interconnect the tube banks Stand 40 Iand lines84 and 86A interconnect the tube banks 42 and 44. In this way possibleuneven heating of the several `streams in the convection section l2 maybe obvlated. For example, if the strearnin tube `bank 38 is not heatedas much as the stream in tube `bank 4U, the interconnecting line` 80will .allow `the two streams to mix and so come to about an equaltemperature and the streams start from this point on an equal basis.Line 88 may be provided to allow mixing of streams intube banks l0 and42 to obviate .any possible uneven heating. Additional interconnectinglines may be used, or, if desired, the interconnecting lines 80, 82, 84,86 and 88 may be omitted.

While I have shown one form of a furnace r and a flow of hydrocarbonfluids therethrough it is to be understood that these are by way ofexample only .and modifications and Achanges may be made withoutdeparting from the spirit of my invention. l

I claim:

1. A furnace adapted for heating hydrocarbon uids which includes aradiant heating `section and a convection heating section separated by abridge wall disposed to extend above the roof of said radiant heatingsection, heater tubes ar,-

ranged along at least one boundary surface of said radiant heatingsection, heatervtubes in said convection heating section andcommunicating with and adapted to receive heated hydrocarbon iiuids fromsaid heater tubes in said radiant heating section, means for supplyinghot combustion products to said radiant heating section for heating thehydrocarbon fluids in the heater"tubes therein, .a wall extendingupwardly from theiroof of said radiant heating section andspaced fromthe upper portion of said bridge wallto form a passageway therewith forconducting hot products of combustion from said radiant heating sectionto said convection heating section, preheater tubes in said passagewayadapted to be heated by the hot products of combustionr passing throughsaid passageway tol preheat hydrocarbon iiuids before passing themthrough said heater tubes in said radiant heating section, a secondpassageway extending over said bridge wall -and communicating with saidiirst` mentioned passageway for conducting products of combustion tosaid convection heating section, and a bypass arranged at the upperportion of said convection heating section above the heater tubestherein and in alinement with the second `passageway which extends oversaid bridge wall whereby part of the hot products of combustion leavingsaid radiant heating section and after passing over said preheater tubesmay be re. moved from said furnace in a substantially straight linewithout passing over the heater tubes in said convection heating sectionto prevent overheating of the hydrocarbon fluids Prassing through theheater tubes in said'convection heating section. v t

2. A furnace adapted for heating hydrocarbon fluids which includes aradiant heating section bridge wall disposed toextend above the roof ofsaid radiant-heating. section, heater tubes arrangedalong' boundarysurfaces of said radiant heating section, heater tubes in saidconvection heating section and in communication with and adapted -toreceive heated hydrocarbon fluids from said heater tubes in said radiantheating section, means for supplying hot combustion products to saidradiant section for heating the tubes therein by direct radiant heat, awall extending upwardly from the roof of said radiant section and spacedfrom the upper portion of said bridge wall to form a passagewaytherewith for conducting substantially all the hot products ofcombustion away from said radiant heating section, preheat'er` tubes insaid passageway for preheating hydrocarbon fluids before passing themthrough said heater tubes in said radiant heating section, saidpassageway extending over said bridge wall for conducting products ofcombustion to said convection heating section, the roof vof said radiantheating section adjacent said passageway being provided with deflectingmeans to direct hot products of combustion into said passageway andprevent short circuiting of the hot products of combustion through onlya portion of said passageway, and a by-pass arranged at Athe upperportion of said convection heating section above the heater tubestherein and in alinement with the portion of the passageway whichextends over said bridge wall whereby part of the hot products ofcombustion leaving said radi-ant heating section and after passing oversaid preheater tubes may be removed from said furnace without passingover the heater tubes in said convection heating section to preventoverheating of the hydrocarbon fluids passingV through ysaid convectionheating section.

3. A furnace adapted for heating hydrocarbon :uids which includes aradiant heating section and a convection heating section separated by abridge wall disposed to extend above the roof of said radiant heatingsection, heater tubes arranged along a boundary surface of said radiantheating section, heater tubes in said convection heating section andin'communication with said heater tubes in said radiant heating section,means for supplying hot combustion products to said radiant heatingsection for heating the heater tubes therein lby direct radiant heat, awall extending upwardly from the roof of said radiant heating sectionand spaced from the upper portion of said bridge wall to form apassageway for conducting'hot products of combustion from said radiantheating section to said convection heating section, preheater tubes insaid passageway for preheating hydrocarbon uids before passing themthrough said heater tubes in said radiant heating section, saidpassageway extending over said bridge wall, and means including aby-pass arranged at the upper portion of said convection heating sectionabove the heatertubes therein whereby part of the hot products ofcombustionleaving said radiant heating section .and after passing 'oversaid preheater tubes may be removed from said furnace without passingover the heater tubes in said convection heating section to preventoverheating of the hydrocarbon fluids passing through said Vconvectionheating section.

t 4. A furnace adapted for heating hydrocarbon fluids which includes aradiant heating section and a convection heating section separated by abridge wall disposed to extend above the roof of said radiant heatingsection, heater tubes arranged along a boundary sur-race of said radiantheating sectionheater tubes insaid convection heating section andincommunication with said heater tubes in said radiant heating section,means for supplying hot .combustion products-to said radiant Yheatingsection, a wall extending upwardly frforn the roof of said radiantsection and spaced from the upperk portion of said bridgewall tof-crm apassageway for conducting all the hot products of combustion `away fromsaid radiant heating section, a preheating section including preheatertubes in saidpassageway for preheating hydrocarbon uids before passingthem through said heater tubes in said radiant heating section, saidpassageway extending over said bridge wall and being in communicationwith said convectionsection, ,and means arranged at the upper portion ofsaid convection heating section above the heater tubes therein wherebyonly a part of the hot iproducts of combustion leaving said preheatersection is passed over the heater tubes in said convection heatingsection to control the heatingl of the hydrocarbon uids passing throughsaid convection heating section.

A5. A furnace adapted for heating lhydrocarbon iiuids .whichincludes'va' radiant heating section anda .convection heating sectionseparated by a bridge wall, heater tubes arranged along boundarysurfaces of said radiant heating section, heater tubes in saidconvection heating section and in communication with-and adapted toreceive heated hydrocarbon fluids from said heater tubes in said radiantheating section,v means for supplying ho-t products of combustionV tosaid radiant heating sec-tion rfor heating the tubes therein by directradiant heat, a wall spaced from said bridge wall to form a passagewaytherewith forconducting substantially all hot products of combustionaway from said radiant heating section and directing them toward saidconvection I heating section, preheater tubes in said passageway forpreheating',hydrocarbon fluids before passing them through saidheatertubes in said radiant heating section, and a by-pass arranged adjacentsaid `convection heating section whereby part of the hot products ofcombustion after leaving said radiant heating section and after passingover said preheater tubes may be remo-ved from said furnace withoutpassing over the heater tubes in said convection heating section toprevent overheating of the hydrocarbon uids passing; through the heatertubes in said convection heating section.

Y 6. A furnace adapted forfheating hydrocarbon fluids which includes aradiant heating section and) a convection heating section separated by abridge wall, heater tubes .arranged along boundary surfaces of saidradiant heating section, heatervtubes in said, convection heatingsection and in communication with and adapted toreceive heatedhydrocarbonfluids from said heater tubes in said radiantheatingcsection, means for supplying hot products of combustion to 4saidradiant heating sectionior heating the tubes therein by direct radiantheat, -a wall'` spaced from said bridge wall to form va passagewaytherewith for conducting 4substantially all hot products of combustionaway fromsaid radiant heating section and directing them ytoward saidconvection heating section, preheater tubesin said passageway forpreheating hydrocarbon iiuids before passing them through said heatertubes in said radiant heating section, said passageway extending ,oversaid bridge wall, and a by-pass arranged at the upper yportion of saidconvection heating section above the heater tubes therein and inalinement with the portion of the passageway A which extends over saidbridge wall whereby the further heating of the hydrocarbon uids in theheater tubes in the convection heating section is controlled `byremoving part of the products of combustion leaving said radiant'section after passing over said preheater tubes and passing the A restof the product-s of combustion over the heater tubes in said convectionheating section,

'7. A- furnace adapted for heating fluids which includes a.radiantvheating section and a convection heating section separated by abridge wall, heater tubes arranged along boundary surfaces or saidradiant heating section, heater tubes in said convection heating sectionand in communiing them toward said convection heating section,

preheater tubes in said passageway for absorbing heat from the productsof combustion passing through said passageway to preheat iiuids beforepassing them through said heater tubes in said radiant heating section,and a by-pass arranged adiacentsaid convection heating section wherebypart of the products of combustion after passing over said p-reheatertubes may be removed from said furnace before passing over the heatertubes i-n said convection section.

8. `In a furnace having radiant and convection heating sectionsseparated by a bridge wall disposed to extend above the roof of saidradiant heating section, the heating sections being provided with heatertubes for conducting hydrocarbon duid to be heated through the furnaceand means for supplying hot products of combustion to said radiantheating section for heating the heater tubes therein by direct radiantheat, the improvement which includes a preheating section havingpreheater tubes positioned in a passageway formed by the upper portionof the vbridge wall and a wall of the furnace, the preheater tubes beingswept by all the hot products of" combustion leaving said radiantheating section for Dreheating the hydrocarbon fluid before it is passedto said radiant heating section, and means for controlling the furtherheating of the hydrocarbon duid passing through the heater tubes in saidconvection heating section, said meansiri'cluding a by-pass whereby apart of the hot products of combustion after passing over said-vpreheater tubes are removed from the furnace and the rest of theproducts of combustion are passed over the heater tubes in saidconvection heating section.

9. An apparatus as deiined in claim 7 wherein the heater tubes in saidconvection section are arranged to subdivide the hearted uid into a'plurality of separate streams and which further includes means wherebythe separate streams may be mixed at least at one point during theirpassage through said convection section to obviate uneven hea-ting ofthe separate streams.

JOHN- HERMAN RICKERMAN.

